Log Information Collecting Device and Log Information Collecting Method

1. A log information collection method for collecting log information of a network device operating in accordance with instructions from an operation apparatus, the log information collection method comprising: determining, in a case that a piece of the log information collected from the network device includes a first character string, whether or not another piece of the log information including a second character string occurs in a predetermined duration before and after a time of occurrence of the piece of the log information including the first character string; generating a new piece of the log information including a third character string using an occurrence or non-occurrence of the another piece of the log information including the second character string in the predetermined duration as a trigger; and accepting, before the determining, and the generating, specifications of the first character string, the second character string, the third character string, the predetermined duration, and occurrence or non-occurrence of the piece of the log information and the another piece of the log information.

2. The log information collection method according to claim 1 , wherein the accepting comprises specifying a plurality of determination conditions including the second character string, the predetermined duration, and the occurrence or non-occurrence of the piece of the log information and the another piece of the log information are acceptable for a single combination of the first character string and the third character string, the determining comprises determining whether each of the plurality of determination conditions specified for the first character string is satisfied, and the generating comprises generating the new piece of log information including the third character string combined with the first character string when all of the plurality of specified determination conditions are satisfied.

3. The log information collection method according to claim 2 , wherein the log information collected from the network device is temporarily stored in a log cache unit, the determining comprises determining whether the log information stored in the log cache unit includes the another piece of the log information including the second character string, and the log information collection method further comprises sequentially deleting the log information in the log cache unit in accordance with the predetermined duration.

4. The log information collection method according to claim 3 , wherein the specifications comprises specifying individual items that are recorded as a determination condition in a determination condition recording unit, the predetermined duration is capable of specifying a pre-determination duration that specifies a duration before the time of occurrence of the piece of the log information including the first character string and a post-determination duration that specifies a duration after the time of occurrence of the piece of the log information including the first character string, and the log information for which time elapses of the pre-determination duration exceeding a period specified by a maximum value of the pre-determination duration recorded in the determination condition recording unit is sequentially deleted.